I was thinking of how simple it would be to do some link swaps on a small scale.
Take 10 different websites, totally unrelated to each other, and have them put up links to the other 9 sites on the front page.
Log where your vistor and hits on the page are at the time the links are put up. After 30 days see if it really made a difference in visits/hits on the partisipating websites. If it doesn't just fold the project and move on. But if it makes a substantial difference, look in to expanding the group.